The central teaching of the Bahá'í Faith is the oneness of humankind. Although wholly associated with the Bahá'í Faith today, it was a very difficult concept for Bahá'ís in earlier times to put into practice in their personal lives. As `Abdu'l-Bahá travelled in the West in 1911 and again in 1912-13, He not only spoke extensively about this principle in numerous meetings but demonstrated its meaning in practical ways and challenged His followers to take up the fight against racism within themselves and their society. This paper looks at `Abdu'l-Bahá's elucidation of the principle of the oneness of humankind in His talks in the West, primarily in the United States, and through His own actions.